The present inventors have disclosed a cooling apparatus using a heat pipe as a semiconductor cooling apparatus for, e.g., a thyristor in Published Unexamined Japanese Patent Application No. 60-57956. As shown in FIGS. 7 and 8, (Prior Art) in this heat pipe semiconductor cooling apparatus, fins 2 consisting of a metal such as aluminum having high heat conductivity are fitted on heat pipes 1 consisting of a metal such as copper having high heat conductivity to form a radiating portion 3. Lower end portions of the heat pipes 1 are fitted in a metal block 4 consisting of, e.g., copper or aluminum. A semiconductor element such as a thyristor is mounted on the metal block 4. Heat generated by the semiconductor element is conducted to the heat pipes 1 and radiated from the fins 2 by natural or forcible cooling. As a result, the operation efficiency of the semiconductor element is improved.
In addition, an insulating heat pipe semiconductor cooling apparatus in which an insulating cylinder consisting of, e.g., aluminum is arranged in an intermediate portion of the heat pipe or a portion between the heat pipe and the metal block has been developed.
In the manufacture of these heat pipe semiconductor cooling apparatuses, boring processing is performed one or a plurality of times for the metal block 4 by using a drill or the like to form (non-through) holes 5 having a predetermined depth. Subsequently, a pre-treatment such as oxide film removal is performed for the holes 5. Thereafter, one end portion of the heat pipe 1 is inserted in the hole 5. A solder 6 or the like is filled in a gap between the heat pipe 1 and the hole 5 to integrally bond the heat pipe 1 and the metal block 4.
In such a conventional method, however, the boring processing is performed by an individual NC (numerically controlled) drill machine. Therefore, a long time period is required for the boring processing, and precision of the processing is poor. In addition, the boring processing increases manufacturing cost.